Hyperglide+ is a smart system that guides the chain when you shift up and down the cassette from one gear to the next. What that means in real world terms is that shifting is smoother, and that’s especially important when you’re shifting under power.
The way they’ve done that is extending the chain’s inner plate to improve the connection between the chain and cassette teeth. By improving and enlarging that contact area, it minimises chain vibration and therefore improves chain engagement, which ultimately ends up in better shifting than ever before.
Changing the freehub design is a pretty radical thing to do and yes, it means that you’ll need a rear wheel with a microspllne freehub to run a 12-speed groupset (although if you’re running DT Swiss wheels all you need to do is switch the freehub body and you’re good to go).
But Microspline is what allows Shimano to use 10t as the smallest sprocket on the new cassettes, increasing gear range even further. It’s a pretty literal name, too, because what they’ve done is make the splines on the cassette smaller and more numerous and smaller splines equals Microspline, get it?
Yep, we get it. Brakes can’t be 12-speed. But it is worth mentioning that along with all the other impressive tech here, 4-piston brakes have come to the Deore level for the first time, too, and use Servo-Wave, a bit of tech that removes the dead stroke when you pull the brake lever.
Essentially, Servo-Wave means that when you pull the brake lever the pads move together quickly, and that speed decreases the further the lever is pulled. So your pads will contact the rotor with less pull at the lever, meaning very little wasted movement.